Key won't turn in ignition, is this the dreaded bad tumbler?
 

I have been reading some threads on this, but I am confused.

I have occasionally had a problem where the key won't turn in the ignition, but if I just wiggled the steering wheel, the ignition would unlock as well as the steering wheel lock. I actually didn't worry too much about this because our other, much newer car has a similar thing where you just have to wiggle the wheel to get the lock disengaged.

Today I was about to leave to go somewhere in my car and found it more difficult than usual to get the wheel/ignition unlocked. After a little wiggling of the wheel while turning the key I got it to turn, but I thought, "hey maybe it is just my worn out copy key." So I took the key out of the ignition, wiggled the wheel to lock it again, and put in my newer dealership key (which I've had for about 1 year, but don't usually use because the rubber guard fell off of it).

Oh how I wish I hadn't done that.

Since then I have not been able to get it to turn again. I tried both keys, a lot of wiggling and turning, squirted some alcohol in there (I read that metal bits can jam it up). Nothing.

I've read about attaching a sander to a key and vibrating it loose, but don't have a sander and don't quite understand the technique.

I also read that the tumbler can have problems according to the angle the car is parked at. I am parked on a slight sideways slant, so I tried jacking up one side to level it out, also didn't help.

I should note that I only seem to remember having this problem when parked in my driveway, which is dirt and uneven.

Also read the diesel giant tutorial on grinding down some pin or something, but I think I need to take out the instrument cluster and look in there to really understand what he's talking about because I can't figure it out by reaching up in there.

Any suggestions on what to try from here are much appreciated.

First off, I would get down to your dealer and order the replacement cylinder from your VIN.

I went ahead and replaced my lock assembly at the same time. Not something I want going bad again. And I don't recall spending $170 on it as APE lists it for. Would need to check my files.

Keep trying with the key though. You might get a small hammer and lightly tap the end of the key. Lithium grease maybe?

take your knee panel down and tap on the lock assembly as well.

But once you get the key to turn, GET THE TUMBLER OUT! Have your paperclip and what not handy. Spin that collar off and pull the switch. You do NOT want to have to resort to the grinding method on the DG site.

My 1978 240D does this frequently in the summer, not so much in the winter. I get around it with the following procedure:

0. Place key in ignition tumbler.
1. Turn key clockwise as far as possible, being careful to avoid damaging the key due to excessive force.
2. Turn the steering wheel anticlockwise as far as possible and with the greatest force possible then turn key clockwise with some force.

Works every time. I am unsure of why the original problem occurs, although it seems to have something to do with the summer heat here in the southeast US. (Heat expansion of lock mechanism? I'm truly just guessing here.)

Thanks for the responses guys. I tried both suggestions and no luck so far.

I plan to keep trying every once in a while hoping it will free up one of these times.

One thing I notice is that if I shake my wheel (to the point where it hits the lock point) the whole lock assembly will wiggle with it. I don't know if this is normal or if it means something is loose.

This usually happens over time. The key will get stuck now & then until you can't turn it at all. If you get it to turn replacing the tumblers will be easy. If not you will need a grinder and patience so keep your fingers crossed that you can get it to turn. If you can get it to work turn your wheel all the way to one side or the other. This will keep the steering wheel lock out of the equation. If the key acts the same it's just the tumbler. If the key is easier to turn it's the entire lock assembly. Either way you will want to be able to turn the key to replace one or both. Otherwise it's crack open a beer time. Oh, what the heck, crack one open anyway.:D

The wafers in the tumbler is hanging up by gunk and not aligned by the key as it should. Spray penetrating oil in the tumbler to loosen up the gunk till you can turn the key. Get the tumbler out asap, replace or repair.

I have a old thread that explains it:(

I have preemptively replaced the tumblers in both my 240's. They hung up periodically and what with all the warnings from forum members to deal with it before it was too late, I heeded them. Don't wait too long!
It is an easy fix.

Yup that works for a while - then one day, you are stuck on unshaded pavement baking in your car trying anything to get that key to turn ONE MORE TIME!!! You sweat and sweat (cause your car has been baking in the sun and you can't get the key to turn far enough to even start the blower, much less the AC), and eventually call a tow truck to get the car somewhere you can disassemble it and Dremmel out your lock pin.....
Ask me how I know....

:rolleyes:

So I have been tapping wiggling, turning... can't get anything to happen.

Luckily it is in my driveway and I can arrange to take a different car for a little bit... but... how long do I go at this before I resort to grinding?

I haven't given up hope that one of these times it will just turn, but no idea if I need to do something different to get it to happen one of these times...

About to go grab a can of WD40...

When you can't stand it sitting there any longer - time to resort to grinding.

It's really not THAT bad - just uncomfortable because of the location.

Of course I am still sporting a nice scar across the back of one of my hands from the time the dremel got away on me under the 240D dash.
:D

I had the same problem. I cant comment in any detail, but I unbolted the ignition assembly, removed it, modified the steering locking pin (the source of my troubles) and made it so that the steering can now never be locked.

NO MORE TROUBLES.

Repair cost: $Zero (out of pocket).
Time: approx 2 hours tops.

You will have to remove the lower access panel. You might want to remove the gauge cluster as well to gain access from above.
Basic tools required.

Easy job.

Best of luck.

First, don't put any grease in a lock, unless you plan to destroy it. Spraying some solvent in there is OK to clean it out or loosen things up. Something that may lubricate temporarily but evaporate is ideal. Locks should be lubricated with a dry lube, i.e. graphite.

This happened to me when I tried to use a key that the ignition was not "used to." I was lazy and didn't want to go upstairs and get key I usually use and used the one that I keep on the key ring for door opening. Well, the ignition lock behaved like you are describing for about a week. I had to "retrain" it with the key I usually use in the ignition for about a week, not taking it out at all. I learned not to take it out and just lock the doors. After a week, I reluctantly took the key out and actuated the ignition and it was just like it always was. Its been about a month since that happened and I haven't had a single issue with it since. No more wiggling, jerking, cussing, or eye rolling.

So, use some alcohol to clean out whatever is in there that anyone has suggested squirting in there, let it dry while you get some graphite dry lube from the hardware store. Take the key the ignition is used to, insert it, move the steering wheel to relieve any pressure on it and pretend your hand is a vibrating instrument :D and apply light torque on it. Hell, if you want, start wiggle the steering wheel side to side lightly hitting the steering lock. I think I recall doing that in times of desperation with success. If you get it to turn, don't take the key out for a while. Of course this is all if you plan not to buy another tumbler.

I recently went to a locksmith who told me not to use graphite. He said silicone lube is better. I'm no expert, though. That's just what he said.

I had the steering lock problem though, two states away from home. I managed to get the key to turn enough to get the tumbler out, then popped the ignition out and rigged the steering lock to never engage again. Haven't had a problem on that car since.

However, I just had the broken tumbler on my 87 300td. I jiggled the key with a pair of vice grips, got it to turn to the second position, and managed to get the tumbler out. If you start having problems, you've got to get that tumbler out asap, or else much larger headaches are coming, and when you least expect them.

But, if you absolutely cant get the key to turn to the second position, time to grind. I've never had to do it, but thanks to my prior problems, I will know when its time to do it.

Sorry, I meant turn the ignition to position 2.